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21.
A new type of energy converter for an electro-mechanical total artificial heart (TAH) based on the principle of a unidirectional moving motor is described. Named the TAH Serpentina, the concept consists of 2 major parts, a pendulum shaped movable element fixed on one side using a joint bearing and a special shaped drum cam. Pusher plates are mounted flexibly to the crossbar of the pendulum. A motor drives the special shaped drum cam linked to the pendulum through a ball bearing. The circular motion of the unidirectional moving brushless DC motor is transferred into the linear motion of the pendulum to drive the pusher plates. Using a crossbar with a variable length, the stroke of the pendulum and therefore the displaced blood volume is alterable. To achieve a variable length, an electric driven screw thread or a hydraulic system is possible. Comparable to the natural heart, cardiac output would be determined by frequency and stroke volume.  相似文献   
22.
The initiation of voluntary movements by the supplementary motor area   总被引:2,自引:0,他引:2  
Summary The hypothesis is formulated that in all voluntary movements the initial neuronal event is in the supplementary motor areas (SMA) of both cerebral hemispheres.Experimental support is provided by three lines of evidence. 1. In voluntary movements many neurones of the SMA are activated probably up to 200 ms before the pyramidal tract discharge. 2. Investigations of regional cerebral blood flow by the radioactive Xenon technique reveal that there is neuronal activity in the SMA of both sides during a continual series of voluntary movements, and that this even occurs when the movement is thought of, but not excuted. 3. With voluntary movement there is initiation of a slow negative potential (the readiness potential, RP) at up to 0.8 s before the movement. The RP is maximum over the vertex, i.e. above the SMA, and is large there even in bilateral Parkinsonism when it is negligible over the motor cortex.An account is given of the SMA, particularly its connectivities to the basal ganglia and the cerebellum that are active in the preprogramming of a movement. The concept of motor programs is described and related to the action of the SMA. It is proposed that each mental intention acts on the SMA in a specific manner and that the SMA has an inventory and the addresses of stored subroutines of all learnt motor programs. Thus by its neuronal connectivities the SMA is able to bring about the desired movement.There is a discussion of the manner in which the mental act of intention calls forth neural actions in the SMA that eventually lead to the intended movement. Explanation is given on the basis of the dualist-interactionist hypothesis of mind-brain liaison. The challenge is to the physicalists to account for the observed phenomena in voluntary movement.Dedicated to Prof. Richard Jung on the occasion of his 70th birthday  相似文献   
23.
24.
Apomorphine (10 mg/kg, s.c.) does not induce in mice a compulsion to gnaw, but pretreatment with cocaine (10–40 mg/kg, i.p.) caused gnawing activity. This effect of cocaine was inhibited by pretreatment with -methyl-p-tyrosine, haloperidol, and physostigmine, but not with FLA-63, phenoxybenzamine and tetrabenazine. These findings would suggest that dopaminergic mechanism plays a significant role in the potentiation of apomorphine gnawing activity by cocaine and also support the view that inhibition of dopamine uptake is responsible for the stimulatory action of cocaine.  相似文献   
25.
针灸治疗单纯性肥胖症及机理研究探讨   总被引:3,自引:2,他引:3  
陈佳红  秦秀娣 《辽宁中医杂志》2003,30(12):1032-1033
单纯性肥胖症是当今社会常见病、多发病之一。近年来 ,针灸治疗单纯性肥胖症无论在临床方面还是在实验机理研究方面 ,均取得较大进展。但针灸减肥的机理研究大多局限在中枢神经核团神经递质含量的研究 ,没有新的突破 ,在临床方面有待于更多、更科学、更规范的临床研究报道。  相似文献   
26.
The influence of reported paternal attitudes on the decision to breast-feed   总被引:1,自引:0,他引:1  
Objective: To identify factors that influence a woman's decision to breast-feed.
Methodology: Five hundred and fifty-six women were recruited from the maternity wards of two Perth hospitals. Data were collected from a self-administered questionnaire completed by participants prior to discharge. Logistic regression analysis was used to determine factors influencing the initiation of breast-feeding.
Results: At discharge from hospital 83.8% of women were breast-feeding, including 6% who were giving complementary formula feeds. After controlling for potentially confounding demographic and biomedical factors, the father's reported preference for breast-feeding was found to be the most important factor influencing a woman's decision to breast-feed (OR 10.18).
Conclusion: Fathers participate in and influence the choice of infant feeding method and should be included in breast-feeding discussions.  相似文献   
27.
着力培育医疗市场营销新机制   总被引:1,自引:0,他引:1  
探讨医疗市场营销问题.通过总结分析桐城市人民医院营销的做法经验,提出着力培育医疗市场营销新机制.  相似文献   
28.
DNA免疫研究进展   总被引:2,自引:0,他引:2  
杨丽琛  杨晓光 《卫生研究》2006,35(1):110-114
DNA免疫可诱导机体全面的免疫应答,且与传统的蛋白免疫相比具有制作简单、经济安全、易于贮存运输等优点。自发现以来已越来越引起人们的重视,成为第三代疫苗,并广泛用于各种感染性疾病的防治研究中。作者主要综述DNA免疫作用机理,可能的影响因素,及其在抗体制备、婴儿免疫、粘膜免疫及表达文库免疫等方面的应用。此外,还介绍了增强DNA免疫效果的策略。  相似文献   
29.
冠状动脉血管成形术后再狭窄的研究现状   总被引:2,自引:0,他引:2  
经皮冠状动脉腔内成形术是目前冠心痛的重要治疗手段,而术后再狭窄的发生严重影响病人的远期疗效与生活质量。本文介绍了再狭窄的发生机制,并从药物、机械、涂层支架、放射及基因方面对再狭窄的防治研究现状进行了综述分析。  相似文献   
30.
从现代风险管理角度,结合医院医疗设备引资(合资)管理实际,发现存在4类风险。探讨了建立医疗设备引资(合资)风险管理体系。包括风险管理流程、风险管理机制、风险规避措施和风险分析方法等方面,以便度时识别、降低和化解存在的风险。  相似文献   
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